Prolactin-secreting pituitary adenoma commonly presents with?

• A. Visual field defects and headaches
• B. Weight loss and tachycardia
• C. Hyperpigmentation
• D. Galactorrhea and amenorrhea (often infertility)

Answer: (D)

Excess prolactin from a pituitary adenoma disrupts the normal hypothalamic control of the menstrual axis. Prolactin inhibits GnRH secretion, which reduces LH and FSH, leading to anovulation and amenorrhea. Prolactin also acts directly on breast tissue to cause galactorrhea. In reproductive-age women, these findings—galactorrhea with amenorrhea—are the classic presentation. If the tumor grows large, it can cause headaches and visual field defects due to optic chiasm compression, but that mass effect is more about larger tumors and isn’t the typical initial presentation. The other symptom clusters listed point to different conditions (weight loss and tachycardia with hyperthyroidism or pheochromocytoma; hyperpigmentation with adrenal issues), so they don’t fit prolactin-secreting adenoma as well.